Thermo-analytical study on stainless steelmaking dust

Abstract

Thermo-gravimetric analyzer (TGA) was used to determine the thermal behavior of stainless steelmaking dust and FTIR was used to detect the components of off-gas. The TGA results indicate that three mass loss/gain stages exist in the thermal process. The mass loss of the dust in the first stage results from the evaporation of moisture and the reaction between dissociated carbon and metal oxides in the dust. The evaporation of moisture within the dust happens at 90–350 °C and the formation of carbon dioxide happens at 250–470 °C. The mass gain of the dust in the second stage results from the oxidation of metals in the dust by the oxygen at 470–950 °C. The third stage is a slow mass loss process, and some metals in the dust are evaporated into the atmosphere in this stage. The evaporation of metals is carried out mainly at 900–1200 °C and the dust is sintered at high temperature over 1200 °C.

Keywords

thermal analysis / stainless steelmaking dust / environmental protection

References

[1] US EPA. 56, 41164. Land Disposal Restriction for Electric Arc Furnace Dust[S]. Federal Register, 1991-08-19.

[2] PengB, LobelJ, KozinskiJ A, et al.. Non-isothermal reduction kinetics of EAF dust-based pellets[J]. CIM Bulletin, 2001, 94(1049): 64-70

[3] LobelJ, PengB, BourassaM, et al.. Pilot-scale direct recycling of flue dust generated in electric stainless steelmaking[J]. Iron and Steelmaker, 2000, 27(1): 41-45

[4] PengB, PengJ, ZhangC, et al.. Thermodynamics calculation on the oxidation and sulfur removal ability of slag in EAF dust pellet reduction process[J]. Journal of Central South University of Technology, 2001, 8(1): 64-68

[5] PengB, ZhangC, PengJ, et al.. Heat transfer model for the reduction of electric arc furnace dust pellets[J]. Metals of Shanghai, 2000, 118(22): 9-13(in Chinese)

[6] PengB, ZhangC, PengJ, et al.. Treatment of electric arc furnace dust[J]. Multipurpose Utilization of Mineral Resources, 2000, 104(4): 33-37(in Chinese)

[7] PengB, ZhangC, PengJ. Treatment of steel-making dust in electric arc furnace by vitrification[J]. Journal of Central South University of Technology, 2000, 31(2): 124-126(in Chinese)

[8] MikhailS A, TurcotteA M, AotaJ. Thermoanalytical study of EAF dust and its vitrification product[J]. Thermochemica Acta, 1996, 287: 71-79

[9] Seeker W R. Waste combustion[A]. Proceedings of the Twenty-third International Symposium on Combustion[C]. The Combustion Institute, 1990. 867–885.

[10] EarnestC MCompositional analysis by thermogravimetry[M], 1988, Philadelphia, ASTM Publication: 272-287